Happens with both stable and technology preview. Page has a service worker and an application cache (for older browsers) I have both the normal Web Inspector open and the Service Worker Web Inspector open When I turn off WiFI and reload I get the following usual banner after a crash. "This webpage was reloaded because a problem occurred" Process: com.apple.WebKit.WebContent [2148] Path: /Applications/Safari Technology Preview.app/Contents/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent Identifier: com.apple.WebKit.WebContent Version: 15610 (15610.1.25.5.1) Build Info: WebKit2-7610001025005001~1 Code Type: X86-64 (Native) Parent Process: ??? [1] Responsible: Safari Technology Preview [2128] User ID: 501 Date/Time: 2020-09-04 17:10:08.702 +0200 OS Version: Mac OS X 10.15.6 (19G2021) Report Version: 12 Anonymous UUID: 2F4AB7D4-49E3-4CAD-E830-5FF371F7024A Time Awake Since Boot: 6200 seconds System Integrity Protection: enabled Crashed Thread: 0 Dispatch queue: com.apple.main-thread Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000 Exception Note: EXC_CORPSE_NOTIFY Termination Signal: Segmentation fault: 11 Termination Reason: Namespace SIGNAL, Code 0xb Terminating Process: exc handler [2148] VM Regions Near 0: --> __TEXT 0000000104dc2000-0000000104dc3000 [ 4K] r-x/r-x SM=COW /Applications/Safari Technology Preview.app/Contents/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent Application Specific Information: Bundle controller class: BrowserBundleController Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 com.apple.JavaScriptCore 0x0000000107ae7fac WTF::JSONImpl::ObjectBase::writeJSON(WTF::StringBuilder&) const + 140 1 com.apple.JavaScriptCore 0x0000000107ae7fb5 WTF::JSONImpl::ObjectBase::writeJSON(WTF::StringBuilder&) const + 149 2 com.apple.JavaScriptCore 0x0000000107ae6a80 WTF::JSONImpl::Value::toJSONString() const + 80 3 com.apple.JavaScriptCore 0x000000010745c182 Inspector::NetworkFrontendDispatcher::responseReceived(WTF::String const&, WTF::String const&, WTF::String const&, double, Inspector::Protocol::Page::ResourceType, WTF::RefPtr<Inspector::Protocol::Network::Response, WTF::DumbPtrTraits<Inspector::Protocol::Network::Response> >) + 1122 4 com.apple.WebCore 0x000000010aab7e76 WebCore::InspectorNetworkAgent::didReceiveResponse(unsigned long, WebCore::DocumentLoader*, WebCore::ResourceResponse const&, WebCore::ResourceLoader*) + 1702 5 com.apple.WebCore 0x000000010aba1ca4 WTF::Detail::CallableWrapper<WebCore::ApplicationCacheGroup::update(WebCore::Frame&, WebCore::ApplicationCacheUpdateOption)::$_18, void, std::experimental::fundamentals_v3::expected<WTF::RefPtr<WebCore::ApplicationCacheResource, WTF::DumbPtrTraits<WebCore::ApplicationCacheResource> >, WebCore::ApplicationCacheResourceLoader::Error>&&>::call(std::experimental::fundamentals_v3::expected<WTF::RefPtr<WebCore::ApplicationCacheResource, WTF::DumbPtrTraits<WebCore::ApplicationCacheResource> >, WebCore::ApplicationCacheResourceLoader::Error>&&) + 4740 6 com.apple.WebCore 0x000000010aba7376 WebCore::ApplicationCacheResourceLoader::cancel(WebCore::ApplicationCacheResourceLoader::Error) + 54 7 com.apple.WebCore 0x000000010aba77fc WebCore::ApplicationCacheResourceLoader::notifyFinished(WebCore::CachedResource&, WebCore::NetworkLoadMetrics const&) + 60 8 com.apple.WebCore 0x000000010abc4d0f WebCore::CachedResource::checkNotify(WebCore::NetworkLoadMetrics const&) + 95 9 com.apple.WebCore 0x00000001092a9dc6 WebCore::CachedResource::error(WebCore::CachedResource::Status) + 502 10 com.apple.WebCore 0x00000001092a9980 WebCore::SubresourceLoader::didFail(WebCore::ResourceError const&) + 816 11 com.apple.WebKit 0x0000000104e19c40 WebKit::WebResourceLoader::didFailResourceLoad(WebCore::ResourceError const&) + 236 12 com.apple.WebKit 0x00000001053064be WebKit::WebResourceLoader::didFailServiceWorkerLoad(WebCore::ResourceError const&) + 278 13 com.apple.WebKit 0x000000010544c72d WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) + 745 14 com.apple.WebKit 0x0000000104e51cfb IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 701 15 com.apple.WebKit 0x0000000104e5450a WTF::Detail::CallableWrapper<IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_7, void>::call() + 214 16 com.apple.JavaScriptCore 0x0000000107b027f1 WTF::RunLoop::performWork() + 529 17 com.apple.JavaScriptCore 0x0000000107b031aa WTF::RunLoop::performWork(void*) + 26 18 com.apple.CoreFoundation 0x00007fff30671d52 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 19 com.apple.CoreFoundation 0x00007fff30671cf1 __CFRunLoopDoSource0 + 103 20 com.apple.CoreFoundation 0x00007fff30671b0b __CFRunLoopDoSources0 + 209 21 com.apple.CoreFoundation 0x00007fff3067083a __CFRunLoopRun + 927 22 com.apple.CoreFoundation 0x00007fff3066fe3e CFRunLoopRunSpecific + 462 23 com.apple.Foundation 0x00007fff32d0b1c8 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 212 24 com.apple.Foundation 0x00007fff32dbdc6f -[NSRunLoop(NSRunLoop) run] + 76 25 libxpc.dylib 0x00007fff6a92a4ea _xpc_objc_main.cold.4 + 49 26 libxpc.dylib 0x00007fff6a92a430 _xpc_objc_main + 559 27 libxpc.dylib 0x00007fff6a929f63 xpc_main + 377 28 com.apple.WebKit 0x0000000104fc89c4 WebKit::XPCServiceMain(int, char const**) + 635 29 libdyld.dylib 0x00007fff6a6dccc9 start + 1 Thread 1:: JavaScriptCore bmalloc scavenger 0 libsystem_kernel.dylib 0x00007fff6a820882 __psynch_cvwait + 10 1 libsystem_pthread.dylib 0x00007fff6a8e1425 _pthread_cond_wait + 698 2 libc++.1.dylib 0x00007fff679af623 std::__1::condition_variable::__do_timed_wait(std::__1::unique_lock<std::__1::mutex>&, std::__1::chrono::time_point<std::__1::chrono::system_clock, std::__1::chrono::duration<long long, std::__1::ratio<1l, 1000000000l> > >) + 93 3 com.apple.JavaScriptCore 0x0000000107b75125 bmalloc::Scavenger::threadRunLoop() + 741 4 com.apple.JavaScriptCore 0x0000000107b74b39 bmalloc::Scavenger::threadEntryPoint(bmalloc::Scavenger*) + 9 5 com.apple.JavaScriptCore 0x0000000107b77247 void* std::__1::__thread_proxy<std::__1::tuple<std::__1::unique_ptr<std::__1::__thread_struct, std::__1::default_delete<std::__1::__thread_struct> >, void (*)(bmalloc::Scavenger*), bmalloc::Scavenger*> >(void*) + 39 6 libsystem_pthread.dylib 0x00007fff6a8e1109 _pthread_start + 148 7 libsystem_pthread.dylib 0x00007fff6a8dcb8b thread_start + 15 Process: com.apple.WebKit.WebContent [1648] Path: /System/Library/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent Identifier: com.apple.WebKit.WebContent Version: 15609 (15609.3.5.1.3) Build Info: WebKit2-7609003005001003~4 Code Type: X86-64 (Native) Parent Process: ??? [1] Responsible: Safari [1375] User ID: 501 Date/Time: 2020-09-04 16:56:31.711 +0200 OS Version: Mac OS X 10.15.6 (19G2021) Report Version: 12 Anonymous UUID: 2F4AB7D4-49E3-4CAD-E830-5FF371F7024A Time Awake Since Boot: 5300 seconds System Integrity Protection: enabled Crashed Thread: 0 Dispatch queue: com.apple.main-thread Exception Type: EXC_BAD_ACCESS (SIGSEGV) Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000 Exception Note: EXC_CORPSE_NOTIFY Termination Signal: Segmentation fault: 11 Termination Reason: Namespace SIGNAL, Code 0xb Terminating Process: exc handler [1648] VM Regions Near 0: --> __TEXT 0000000103458000-0000000103459000 [ 4K] r-x/r-x SM=COW /System/Library/Frameworks/WebKit.framework/Versions/A/XPCServices/com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent Application Specific Information: dyld3 mode Bundle controller class: BrowserBundleController Thread 0 Crashed:: Dispatch queue: com.apple.main-thread 0 com.apple.JavaScriptCore 0x00007fff34deb0d8 WTF::JSONImpl::ObjectBase::writeJSON(WTF::StringBuilder&) const + 168 1 com.apple.JavaScriptCore 0x00007fff34deb0e1 WTF::JSONImpl::ObjectBase::writeJSON(WTF::StringBuilder&) const + 177 2 com.apple.JavaScriptCore 0x00007fff34de9810 WTF::JSONImpl::Value::toJSONString() const + 80 3 com.apple.JavaScriptCore 0x00007fff34800b32 Inspector::NetworkFrontendDispatcher::responseReceived(WTF::String const&, WTF::String const&, WTF::String const&, double, Inspector::Protocol::Page::ResourceType, WTF::RefPtr<Inspector::Protocol::Network::Response, WTF::DumbPtrTraits<Inspector::Protocol::Network::Response> >) + 1122 4 com.apple.WebCore 0x00007fff408062ec WebCore::InspectorNetworkAgent::didReceiveResponse(unsigned long, WebCore::DocumentLoader*, WebCore::ResourceResponse const&, WebCore::ResourceLoader*) + 1772 5 com.apple.WebCore 0x00007fff408d4678 WTF::Detail::CallableWrapper<WebCore::ApplicationCacheGroup::update(WebCore::Frame&, WebCore::ApplicationCacheUpdateOption)::$_17, void, std::experimental::fundamentals_v3::expected<WTF::RefPtr<WebCore::ApplicationCacheResource, WTF::DumbPtrTraits<WebCore::ApplicationCacheResource> >, WebCore::ApplicationCacheResourceLoader::Error>&&>::call(std::experimental::fundamentals_v3::expected<WTF::RefPtr<WebCore::ApplicationCacheResource, WTF::DumbPtrTraits<WebCore::ApplicationCacheResource> >, WebCore::ApplicationCacheResourceLoader::Error>&&) + 5128 6 com.apple.WebCore 0x00007fff408d80e6 WebCore::ApplicationCacheResourceLoader::cancel(WebCore::ApplicationCacheResourceLoader::Error) + 54 7 com.apple.WebCore 0x00007fff408d845c WebCore::ApplicationCacheResourceLoader::notifyFinished(WebCore::CachedResource&) + 60 8 com.apple.WebCore 0x00007fff3f1408ac WebCore::CachedResource::checkNotify() + 92 9 com.apple.WebCore 0x00007fff3f1f7ad6 WebCore::SubresourceLoader::didFail(WebCore::ResourceError const&) + 662 10 com.apple.WebKit 0x00007fff41573d01 WebKit::WebResourceLoader::didFailResourceLoad(WebCore::ResourceError const&) + 233 11 com.apple.WebKit 0x00007fff419b5178 WebKit::WebResourceLoader::didFailServiceWorkerLoad(WebCore::ResourceError const&) + 278 12 com.apple.WebKit 0x00007fff41ade7e3 WebKit::WebResourceLoader::didReceiveWebResourceLoaderMessage(IPC::Connection&, IPC::Decoder&) + 511 13 com.apple.WebKit 0x00007fff415ac82b IPC::Connection::dispatchMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >) + 209 14 com.apple.WebKit 0x00007fff415af450 WTF::Detail::CallableWrapper<IPC::Connection::enqueueIncomingMessage(std::__1::unique_ptr<IPC::Decoder, std::__1::default_delete<IPC::Decoder> >)::$_7, void>::call() + 214 15 com.apple.JavaScriptCore 0x00007fff34e06df9 WTF::RunLoop::performWork() + 473 16 com.apple.JavaScriptCore 0x00007fff34e06ffa WTF::RunLoop::performWork(void*) + 26 17 com.apple.CoreFoundation 0x00007fff30671d52 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17 18 com.apple.CoreFoundation 0x00007fff30671cf1 __CFRunLoopDoSource0 + 103 19 com.apple.CoreFoundation 0x00007fff30671b0b __CFRunLoopDoSources0 + 209 20 com.apple.CoreFoundation 0x00007fff3067083a __CFRunLoopRun + 927 21 com.apple.CoreFoundation 0x00007fff3066fe3e CFRunLoopRunSpecific + 462 22 com.apple.Foundation 0x00007fff32d0b1c8 -[NSRunLoop(NSRunLoop) runMode:beforeDate:] + 212 23 com.apple.Foundation 0x00007fff32dbdc6f -[NSRunLoop(NSRunLoop) run] + 76 24 libxpc.dylib 0x00007fff6a92a4ea _xpc_objc_main.cold.4 + 49 25 libxpc.dylib 0x00007fff6a92a430 _xpc_objc_main + 559 26 libxpc.dylib 0x00007fff6a929f63 xpc_main + 377 27 com.apple.WebKit 0x00007fff4171a006 WebKit::XPCServiceMain(int, char const**) + 539 28 libdyld.dylib 0x00007fff6a6dccc9 start + 1
rdar://problem/41155976